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Wakespeed WS500 Compared To ARCO Zeus—What Matters

Given that so many influencers these days are being paid in various ways, let me be clear. AAC and I don’t get a penny if you buy a Wakespeed or a Zeus. Zip, nada, zilch. I work for our members. They are the only bosses I have.

That said, and for the sake of total disclosure, Wakespeed have given me two regulators for evaluation (soon to be three), but if you think I can be bought that cheap, you are mistaken.

The value of three regulators is trivial compared to the total that over 5000 members pay us each year. I know who butters my bread…and supplies the loaf.

Before we dig into which smart alternator regulator to buy, a note on my background:

This is not a quick review by some yachtie with a little technical experience. I founded and ran a tech company (computer-systems integrator) where our success was continually dependant on my ability to pick good high-tech products.

And, yes, I made mistakes…which taught me a lot, and which I have applied to evaluating these two products.

So even if you’re not interested in buying an alternator regulator, it’s worth your time to scan through these articles (might be two parts) and then read the conclusions, since it’s a graphic demonstration of how to cut through slick marketing, much of it fuelled by payments to influencers, to get to the right selection.

And lest you think that my background gives me all the answers, I learned a personal lesson while installing the Wakespeed—heeding it could save you a lot of aggravation.


Let’s start with the 800-lb gorilla in the room. The ARCO Zeus comes with Bluetooth built in and the Wakespeed WS500 does not.

Huge win for the Zeus making the WS500 obsolete, right? Wrong.

Never mind that rumour has it that this advantage will go away soon, let’s look at this from the product evaluation point of view.

Spoiler: Even in a situation where one regulator has Bluetooth and the other not that’s not what’s important. Read on for what is.

So let’s think about why we all want Bluetooth so desperately—including me, given I have been beating on Wakespeed about it for three years.

No, it’s not monitoring, or it shouldn’t be given we can monitor the regulator in other and better ways—I can flesh that out in Part 2 if there’s enough interest.

So what’s really driving us? That’s easy, I just need to look in the mirror.

Deep down many of us think we are super-smart and can configure a complex regulator to match our alternator and batteries better than anyone else. We want control, damn it!

Let me tell you a story:

I’m just that kind of super-smart guy (just ask me) who clearly understands how alternator regulators work—heck, I’m an electronics tech by trade who was the first to figure out and publish how to program a Balmar regulator so it didn’t wreck lead-acid batteries. I understand this stuff.

So when I installed my WS500 I went straight to expert mode in the Wakespeed app to program everything just the way I wanted it.

I set up my installation using my three decades of experience with lead-acid batteries and programming regulators and…it didn’t work. The regulator just gave me a sullen look and refused to turn the alternator on.

I then started troubleshooting and determined for absolute certain that Wakespeed had sent me a bad harness. So I called Al Thomason, co-founder and chief engineer at Wakespeed1. Here’s the conversation:

A: Were you in expert mode?

J: Yes.

A: Do a factory reset and try it.

J: But it’s the harness, Al, I know it is.

A: Humour me, John.

J: Oh, OK…

A: Is it working now?

J: Sorry, Al, I can’t hear you, must be a bad connection…click.

Yes, I had made one small stupid mistake. But in my defense the WS 500 has a lot more settings than other regulators I’m used to, which contributed. And that illustrates my point:

These new regulators, both the Zeus and the WS500, are far more powerful and feature rich than anything that’s come before, so people like me with a lot of experience with the previous generation of regulators can get a surprise.

The more powerful and flexible a device is the easier it is to screw it up.

Hold that thought.

A Better Way

So, after wiping the egg off my face, I selected my batteries and alternator by manufacturer and model number from the pull-down menu in the Wakespeed app, downloaded the configuration into the WS500, and it worked great. That was ages ago, and the last time I have thought about it.

Now, of course you are all smarter than I am and will get the expert settings right the first time, but, even so, why on earth do you want the hassles of trying to figure this out by reading all the manuals and then programming each setting, when you don’t need to?

Al at Wakespeed has already figured out the settings we need for most-all configurations, while consulting directly with the engineers who developed the battery and/or BMS in question. Not people who are going to talk to us while we home brew this stuff.

That said, there’s no question that ARCO are hard at work coming up with preconfigured configurations, just like Wakespeed. These people are far from stupid and clearly understand that having many good configurations available is a big part of Wakespeed’s secret sauce.

And while I’m giving kudos to ARCO, their app has useful explanations of each setting, which the Wakespeed app does not do as well.

What Matters

All that’s interesting, but let’s get back to what really matters when choosing between the two alternator regulators:

  1. Which has a tested and proven configuration for our batteries, and BMS if lithium.
  2. Being very sure we understand what level of process control is actually being offered.

Claims and Reality

Let’s dig a bit deeper into number two. It’s easy just to look at, for example, the above-linked PDF over at ARCO and assume that the Zeus has already caught up to the WS500.

But wait, I have it directly from a Zeus dealer that ARCO have, for example, not yet even got the unit working properly over CAN bus with Victron Lynx.

Al at Wakespeed had this cracked years ago. Never mind the next step, Victron DVCC integration, which Wakespeed just announced.

Could that dealer be wrong, or out of date? Sure.

Will ARCO someday get all that done for all the configurations that Wakespeed already have cracked? Probably.

But not quickly.

And are Wakespeed going to sit on their hands while ARCO catch them up?…Wait two months if you believe that.

This Is Hard

Back to how hard this is.

For example, using CAN bus to talk to a BMS is way, way more complicated than most people think. Heck, there are at least four different transmission protocols, and almost all the BMS vendors use different ones from each other.

In most cases, Al has had to work with the engineers who designed each BMS to modify their own code so any alternator regulator can do a good job—ARCO should send him a thank you gift. This is seriously tricky stuff.

And there are no cross-vendor standards like with NMEA 2000—that’s coming (maybe), but it’s not here.

Cracking all this is going to take ARCO a while, and I’m betting it will be buggy for quite a while after that. It’s just the nature of software that’s required to get two complex devices working together, particularly ones that were built by two different companies.

Al’s (Probably) Unassailable Lead

Al Thomason, the guy in charge at Wakespeed, is a real cruiser who has been deeply immersed in alternator regulators since he home brewed the ancestor to the WS500 in 2011, while living aboard and cruising his Monk-designed trawler. Counts on fingers…that’s 13 years.

And WakeSpeed, the company Al founded, have literally tens of thousands of WS500 regulators out there in the field working reliably in every conceivable configuration.

Do we really think that ARCO have passed him by in the few months since they released their product?

Your call, but I don’t.

In fact, the thing that made me most sceptical about the Zeus regulator right from the beginning is that the initial announcement claimed that they had it all figured out.

In my experience, that’s a danger signal and a common symptom of a product sold by a company where the marketers are in control, not the engineers who have to actually deliver a working bug-free product.

Heck, it takes Al about a month of bench testing to certify the WS500 to work properly with each lithium battery and BMS—probably less for lead acid. Once again, do we really think that ARCO have all that done already?


So here is my current recommendation:

No matter what battery chemistry you are using, don’t be a pioneer with the Zeus, buy a Wakespeed instead—in a couple of months, if you can wait—to get:

  1. Many more proven configurations.
  2. Deeply integrated configurations; for example, full-on CAN bus integration, and next-level stuff like Victron DVCC.
  3. A years-long track record of reliable operation.
  4. Al Thomason’s 13 years of experience.

The rest is small stuff.

And if you need a regulator right now? Still buy a WS500. The above four benefits outweigh Bluetooth by a country mile—you want sausage or sizzle?


I genuinely think that the Wakespeed is the best smart regulator out there, at least right now. Could I be wrong?

Of course, only idiots, or people getting affiliates payments (kickbacks), are certain about anything this complex.

But, even if I am wrong, the WS500 is still a good, proven and reliable product.

Or, to put it another way, going with a WS500 has low downside risk, which, at least to those of us who actually want to get out there cruising is by far the most important selection criteria.

Of course that begs the question, “If we apply that thinking, how does a new and innovative product get traction?”. And I agree that supporting innovation is important, that’s why I was all over the WS500 when it was released—it seriously moved the needle.

But the ARCO Zeus is just a me-too product2 trying to piggyback on Wakespeed’s success—nothing new except Bluetooth, which as we see above is not that significant, and even that advantage goes away soon…oops, who said that?

Stuff I Learned

This was an interesting exercise, but, at least to me, the biggest payoff was the stuff I learned:

  1. A lot of us want complete control of every detail of our electrical systems, but is that even a good idea? Might it be better to buy a proven good product with standard configurations and not mess with it? Worth thinking about.
  2. Many of us (including me) are not as smart about this stuff as we like to think we are. A bit of humility can save us a lot of time, money and aggravation…and egg on face.
  3. Fixating on one cool feature like Bluetooth can blind us to what really matters.

Part 2

You still want the small stuff?

OK, if there’s enough interest (leave a comment), I will dig into a bunch in Part 2. Things that come to mind as interesting:

  • Why all Wakespeed regulators have a USB port and why that should make us happy not sad.
  • Why not having Bluetooth on a legacy WS500 doesn’t matter much.
  • One or two shunts, or maybe none.
  • True ease of use.
  • Dangers of Bluetooth.
  • Manufacturing quality.

Further Reading

Much more on building reliable electrical systems for cruising boats:

  1. One of the great things about my job is that I have access to people like Al who are not normally available for support calls, particularly stupid ones like mine. That said, Al, even today, still does third-level support when a problem is beyond the first and second levels. Does him credit. ↩︎
  2. Me-too products are useful too, because they tend to push the incumbent to keep up and continue to innovate. ↩︎
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Ross Hubbard

Thank you, John, good information as usual. It is saving me from my overthinking self.

Please do continue with more information on Wakespeed and ZEUS.


Tim Ketteridge

I’d like to see the Part 2, thanks for writing this article.

Vesa Ikonen

Part 2 please 🙂

Daniel McCarty

Channeling Vesa….

Part 2, please Sir. 🙂

Stein Varjord

Hi John,
To prove you right, yes I’d also like to read more about your thoughts on this, since I also tend to put myself in the expert seat, even when I shouldn’t. And I do think I’ll be getting a couple of these in the not too distant future.

Ben Logsdon

These articles are very timely as I’m planning on an electrical system upgrade in the next couple years…we should have a lot of the esoteric stuff regarding Li batteries and charging controls disucssed. Transparency like this is invaluable and I’m glad to be one of your bread butterers!

Denis Foster

Thanks John, I am waiting for part 2.

side question Can you have two shunts measuring in and out of the same circuit. How do you install this?

Evan Effa

Hi Denis,

I was concerned about this question and according to Arco, you have a Victron BMV shunt, the Zeus can use this shunt’s data directly (just add twisted pair wires.)


Evan Effa

Oops. *if you have a Victron BMV…

Paul Y

I was the boat we found the WS bug. Looks like Victron samples the shunt digitally. So does WS. If you use the same shunt for both, they drive noise and the WS sampling is all over the place. I told Zeus to watch out for this during development.
You can piggyback on the board attachment screws fine physically, its an RF/Electrical noise problem.
I solved it with a second shunt inline.

Evan Effa

Thanks John for opening this comparison again; but, I think we will all look forward to your unpacking the real testing details… (that’s the place where the devil / Mr Murphy lives.)

I’ve been in the throes of looking at these two regulators for my system as the Balmar MC-612 is pretty limited in its configurability.

DVCC & Canbus integration with integration of shunt-derived state of charge monitoring seems to be the Holy Grail and represents a compelling goal to both Wakespeed & ARCO (if for no other reason than good marketing)?

In my own EPOCH LFP setup though, I am not convinced it’s necessary or all that desirable to go to DVCC, Cerbo GX control with its extra layers of complexity. Unlike lead acid, where internal resistance grows larger with higher SOC, necessitating higher voltages to optimize charging efficiency, and a real need to use real-time SOC data to regulate charging, the Epoch LFP’s take all the charging I throw at them and by the time the bank hits 13.9 VDC, the bank is at 99.9% SOC. It really is a lot simpler.

I would ideally want a smart regulator that is very good at tight control of charging voltages, maintains safe alternator loads by monitoring alternator temps and output and would be able to turn off charging in the event of a BMS shutdown. (load dump). Both the Wakespeed & Zeus can probably do these things well but I have yet to read of a proper testing comparison between the two.

In this respect, ie communication of impending load dump, Canbus communication has real value but the actual charging protocol is pretty simple. (eg Victron IP22 protocol of 13.9 VDC Bulk/ with very short absorption time & 13.45 VDC Float has my bank well topped up & balanced.)

Unfortunately, in my setup, the Epoch BMS’s do not, at present, have a way to communicate an impending MOSFET shutdown despite their Victron Canbus integration. This means that, until I can protect against a load dump, I will stick with my Dumb Balmar regulator to feed the AGM start & thruster banks & use Orion XS DCDC chargers for the alternator to charge the LFP’s.

Evan Effa

Hi John.

I’m not suggesting for a moment that one does not want accurate SOC or current monitoring with LFP.

I’m simply saying that, unlike lead acid battery banks where one needs more prolonged absorption times to achieve a full SOC and ideally using smart chargers & regulators that monitor and control charging according to SOC goals, LFP is a much simpler protocol.

Yes. I’ve read that article thanks.

Torsten Hansen


Only 5000 subscribers? That blows me away. I consider my membership essential and can’t think of another site with so much common sense and experience based advice. Your articles help me make important decisions during our refit and so cut down on the agonizing, slab reef at the mast and PC based navigation come to mind as big ones but there are others. Thank you for that.

May I suggest to any member reading this that you go out and find just one new subscriber to support AAC?

I’m looking forward to part two of this series and hoping for as much detail as possible. Maybe part three could be an in-depth look at the Whitespace concept and how to best implement it. My engine and Wakespeeds will thank you. We will be running two 24V, 140 Amp Balmars on a Beta 60.

Eric Klem

Hi Torsten and John,

I am not familiar with the term whitespace in this context. Are you discussing taking advantage of the mismatch of the prop curve and engine power curve to allow for high output and potentially efficient charging at mid-range engine speeds?


Eric Klem

Hi John,

Thanks, I downloaded the app and took a look. I am so glad that someone is finally allowing this level of control.

I put an article on how to optimize this on my list, it is certainly worth thinking about also as we are starting to see some really powerful alternators on relatively small engines. It is also related to 2 articles I was already thinking of on drivetrain efficiency related to propellers and with big alternators, including how to deal with the alternator output when propping really makes a difference.


Dick Stevenson

Hi Eric and all,
For years, I have had a field wire disconnect switch which takes my alternator off line. Early on I had a smaller engine which occasionally had to work hard to get out of rivers when wind was vs river stream and I wanted all power to be able to get to the prop, especially with the alt working hard and taking hp after a few days at anchor.
I am almost embarrassed to admit that the more compelling reason was the occasional wish to use the microwave when motoring: I did not like hammering the alternator, the belt etc. when the current draw of the microwave kicked in. So, take the alt reg off line and use the microwave and when the microwaving is done, bring the alt reg back on line: it ramps up and gently replaces the amperage used and no hammering of the alt, the belt etc.
I never did need to use the disconnect to get full power to the prop, but it was there if necessary.
My best, Dick Stevenson, s/v Alchemy

Steven Berl

Looking forward to part 2

Colin Post

Hi John. Thank you so much. I was about to lay down my $800 US for a Zeus. I liked the idea of NOT needing to select a positive or negative harness as one needs to do with the Wakespeed. I have very old instruments on my CS 30, soon to be replaced. So the CANBUS is now in the picture. Having the electronics able to communicate plus having good battery monitoring appeals to me. I absolutely need a system that just works. Full stop. Again, thank you for the clear no B.S. assessment. I too wouldvery much like to see part 2.

Colin Post

Kit Laughlin

John, very good, as usual, and I’m interested in part 2.

Lewis Reed

I enjoyed the article, John, especially since one of my next projects is to upgrade one of my alternators and install an external regulator for it. I’m looking forward to Part 2. Many thanks!

Steve Jackson

Part 2. Yes please. I’m considering changing my alternator regulator at the end of the season, so Part 2 will be extremely useful to me. Thanks

Paul Y

I run a WS500 and APS 56v alt on a cat, and there are some unresolved issues with the product. On a cat the regulator must be near either the battery or the engine room, cant be both. That means extending the loom. The loom is very noise sensitive, and extending either the batt shunt or alt temp sensor gives problems unless you shield well. Thats undocumented.

The temp control on my and others boats can oscillate wildly. The damping applied is not adjustable and oversensitive. You need to faff around with sensor location to get smooth temp control for steady output.

In both cases above the sampling and actions happen too fast to show up in the debug output, so you dont really know whats driving the switching.

The rotor field is fully powered when the engine is stopped. Heat. It could ramp back, but it doesn’t. I ran mine though a relay with the oil pressure sensor.

N2K documentation for BMS integration is terrible. You can’t determine what parameters the BMS is controlling and what the WS is controlling. Who is in charge of what and when? The answer is both, sometimes.

Programming, well, you know that interface.

WS is a fascinating product, but has very large gaps and the aquistion hasnt helped.

They have / had amazing support, really nice guys, but the product has long term large gaps.

Paul Y

48v boat w 30kwhr batt and 9kw alternator. No profile for that setup.
The warning in the manual came from us working w Al to track it down a bit over 2 yrs ago.
They are very noise sensitive in most respects. Engine room is about 5m from batts, so loom has to be long one way or the other.
When integrating Victron, REC and WS, also whilst guineapigging the Wifi router thing from their partner, CAN was very very problematic.
Ended up following TopSecret and keeping discrete control. Much more reliable.

James Pokorski

Looking forward to part 2. I have a WS500 controlled Balmar, charging a 24v Victron SmartBattery bank through a Lynx BMS. Lacking a shunt for the alternator, not sure I have it optimally configured. However, the system has exceeded expectations for the past year and a half, cruising full tome.


Karl Lewis

I’d like to join the chorus asking for Part Duex. Yes, please.

William Bowers

Great piece John.

I am excited to have finally brought up our WS500 under the long awaited new 2.5.2 firmware which supports full integration with the Victron Cerbo / Smart BMS integrated DVCC multisource charging control and the elegant Whitespace rpm driven charge programming. I have a screen shot of the first run to share.

I highly recommend Off Grid and Marine Energy Systems for their elegant Wakespeed Software Configuration Tool. The Pro version is worth every penny. It does real time graphing and data logging. Tab to Configure and it parses and geo-annotates the png parameters and allows editing back to the WS500. And the Wakespeed dashboard is glassbridge sexy and super helpful.

3 Cheers to Al, Victron, and OGM!

Bill Bowers
SV ConverJence